Video camera with multiple fields of view

Abstract

A method and apparatus for generating a video signal representing an image of a scene, by: providing a photodetector having a light sensitive surface with a given area; providing a first focusing lens; positioning the first lens to focus an image of a scene on the photodetector so that only a portion of the image is focused on the light sensitive surface; and effecting relative displacement between the first lens and the photodetector parallel to the light sensitive surface in order to change the portion of the image that is focused on the light sensitive surface.

What is claimed is:  
     
         1 . A method of generating a video signal representing an image of a scene, comprising: 
 providing a photodetector having a light sensitive surface with a given area;    providing a first focusing lens;    positioning the first lens to focus an image of a scene on the photodetector so that only a portion of the image is focused on the light sensitive surface; and    effecting relative displacement between the first lens and the photodetector parallel to the light sensitive surface in order to change the portion of the image that is focused on the light sensitive surface.    
     
     
         2 . The method of  claim 1  wherein the first focusing lens has an optical axis that traverses the light sensitive surface, and said method further comprises: 
 providing a second focusing lens having an optical axis which traverses the light sensitive surface;  
 positioning the second lens to focus an image of a scene on the photodetector; and  
 effecting a second relative displacement between the lenses and the photodetector parallel to the light sensitive surface between a first position in which a portion of the image formed by the first lens is focused on the light sensitive surface and a second position in which at least a portion of the image formed by the second lens is focused on the light sensitive surface.  
 
     
     
         3 . The method of  claim 2  wherein during said step of effecting relative displacement, the first and second lenses remain fixed in position relative to one another.  
     
     
         4 . The method of  claim 3  wherein the first and second lenses have respectively different focal lengths.  
     
     
         5 . The method of  claim 4  wherein the second lens has a shorter focal length than the first lens.  
     
     
         6 . The method of  claim 5 , further comprising: 
 selecting a portion of the scene focused by the second lens on the photodetector; and    effecting relative movement between the first lens and the photodetector to cause the first lens to focus the selected portion of the scene on the photodetector.    
     
     
         7 . Apparatus for generating a video signal representing an image of a scene, comprising: 
 a photodetector having a light sensitive surface with a given area;    a first focusing lens;    means for positioning the first lens to focus an image of only a portion of a scene on the light sensitive surface; and    means for effecting relative displacement between the first lens and the photodetector parallel to the light sensitive surface in order to change the portion of the image that is focused on the light sensitive surface.    
     
     
         8 . The apparatus of  claim 7  wherein the first focusing lens has an optical axis that traverses the light sensitive surface, and said apparatus further comprises a second focusing lens having an optical axis which traverses the light sensitive surface, and wherein 
 said means for positioning are operative for positioning the second lens to focus an image of the entire scene on the light sensitive surface; and  
 said means for effecting relative displacement are operative for effecting a second relative displacement between the lenses and the photodetector parallel to the light sensitive surface between a first position in which a portion of the image formed by the first lens is focused on the light sensitive surface and a second position in which at least a portion of the image formed by the second lens is focused on the light sensitive surface.  
 
     
     
         9 . The apparatus of  claim 8  wherein the first and second lenses remain fixed in position relative to one another during the relative displacements.  
     
     
         10 . The apparatus of  claim 9  wherein the first and second lenses have respectively different focal lengths.  
     
     
         11 . The apparatus of  claim 10  wherein the second lens has a shorter focal length than the first lens.  
     
     
         12 . The apparatus of  claim 8  wherein said means for effecting relative displacement comprise: 
 a support base having a surface;  
 a first plate mounted on the support plate;  
 a first translator for displacing the first plate in a first direction parallel to the surface;  
 a second plate mounted on the first plate; and  
 a second translator for displacing the second plate in a second direction parallel to the surface and perpendicular to the first direction, wherein, the photodetector is mounted in the surface or on the first plate and the lenses are mounted on the second plate.  
 
     
     
         13 . The apparatus of  claim 7  further comprising, 
 a second photodetector having a second light sensitive surface;  
 a second focusing lens; and  
 means for positioning the second lens to focus an image of the entire scene on the second light sensitive surface.